OBJECTIVE: To examine whether polymorphisms within the estrogen receptor a (ERa) and ERb genes are susceptibility factors for human male idiopathic infertility in Chinese men.

STUDY DESIGN: We investigated the association between the ERa gene PvuII and XbaI and ERb gene RsaI and AluI polymorphisms and idiopathic male infertility in Chinese Han males. A total of 204 oligozoospermic (sperm count <20x10 /mL) or azoospermic males and 252 fertile control males were included in this study.

RESULTS: The analysis revealed a strong association between the XbaI genotype distribution and impaired spermatogenesis (p=0.0018). The frequency of the G allele was significantly lower in the infertility patients than in the controls (p=0.003). Furthermore, serum levels of follicle-stimulating hormone and luteinizing hormone in patients were significantly higher in XbaI AA carriers compared to AG or GG carriers.

CONCLUSION: Our findings further support a possible role of ERa on male infertility. Further studies are needed to replicate our findings as well as to better elucidate the biological mechanisms of the modulation of ERa on human spermatogenesis.